var _POPUP_FEATURES = 'location=0,statusbar=0,directories=0,width=400,height=300';
function raw_popup(url, target, features) {
    if (isUndefined(features)) features = _POPUP_FEATURES;
    if (isUndefined(target  )) target   = '_blank';
    var theWindow = window.open(url, target, features);
    theWindow.focus();
    return theWindow;
}
function link_popup(src, features) {
    return raw_popup(src.getAttribute('href'), src.getAttribute('target') || '_blank', features);
}
function help_popup(src, features) {
    var target = src.getAttribute('target') || '_blank';
    var url = src.getAttribute('href');
    if (isUndefined(features)) features = _POPUP_FEATURES;
    if (isUndefined(target)) target = '_blank';
    var w = screen.width / 3;
    var h = screen.height;
    var screenX = screen.width - w;
    var screenY = 0;
    var newfeatures = 'width=' + w + ', height=' + h + ', left=' + screenX + ', top=' + screenY + ', ' + features;

    var theWindow = window.open(url, target, newfeatures);
    theWindow.resizeTo(w, h);
    theWindow.focus();
    return theWindow;
}
function isUndefined(v) {
    var undef;
    return v===undef;
}
